Comparative Passage of Sr 85 and Ca 45 from Plasma into Body Fluids in Man. ∗

Abstract

Summary

The passage of strontium and calcium from plasma into peritoneal, pleural and interstitial fluids has been studied in man following intravenous injection of Sr⁸⁵ and Ca⁴⁵. Rates of passage of the 2 isotopes into peritoneal cavity have been calculated. In 1 case, Ca⁴⁵ entered the cavity more rapidly than Sr⁸⁵, in another, Sr⁸⁵ entered more rapidly, and in 2 cases, both radioisotopes entered at the same rate. Both ions passed more rapidly into and out of the peritoneal cavity than the fluid accumulated, but passage of ions was slower than flow of water. Rate of passage varied in different patients as did ratio of rates for Sr⁸⁵ and Ca⁴⁵. The high protein content indicated that peritoneal fluid was not an ultrafiltrate although the Sr⁸⁵/Ca⁴⁵ ratio corresponded to that of an ultrafiltrate in some cases. The ratio in pleural fluid approximated that of an ultrafiltrate. Sr⁸⁵ entering more rapidly. The ratio of passage of Sr⁸⁵ and Ca⁴⁵ into interstitial fluid studied in one patient with massive edema indicated increased permeability of the capillaries, both isotopes entering the fluid at about the same rate.